LC filter

Abstract

An LC filter having electrode layers formed on opposite surfaces of a dielectric substrate. This filter includes a line electrode formed on one surface of the dielectric substrate. The line electrode extends from one electrode layer along outer edges of other electrode layers.

What is claimed is: 
     
       1. An LC filter having a capacitor-inductor combination, comprising: a dielectric substrate;   at least one pair of capacitor electrode layers formed on a top surface and a bottom surface, respectively, of said dielectric substrate at opposite positions across said dielectric substrate;   at least one inductor electrode layer formed on at least one surface of said dielectric substrate for constituting an LC circuit with said capacitor electrode layers; and   a line electrode formed on said one surface of said dielectric substrate to extend from an electrode layer along outer edges of one of the capacitor electrode layers and the at least one inductor electrode layer, wherein an attenuation pole is formed to increase attenuation in a high frequency range with respect to a passband.   
     
     
       2. An Lc filter as claimed in claim 1, wherein said line electrode extends linearly. 
     
     
       3. An LC filter as claimed in claim 1, wherein said inductor electrode layer comprises printed coil in spiral form. 
     
     
       4. An LC filter as claimed in claim 1, wherein the capacitor electrode layers and the inductor electrode layer form a parallel circuit of a capacitor and an inductor connected between an input terminal and a grounding terminal, and a series circuit of a capacitor and an inductor connected between the input terminal and an output terminal, said line electrode comprising LC series element inserted between the grounding terminal and an intermediate connecting point in the series circuit of the capacitor and the inductor.